Probing the nature of the χc1(3872) state using radiative decays by Aaij, R., Abdelmotteleb, A. S. W., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adefisoye, A. A., Adeva, B., Adinolfi, M., Adlarson, P., Agapopoulou, C., Aidala, C. A., Ajaltouni, Z., Akar, S., Akiba, K., Albicocco, P., Albrecht, J.

“…Using the B+ → χc1(3872)K+ decay, the χc1(3872) → ψ(2S) γ process is observed for the first time and the ratio of its partial width to that of the χc1(3872) → J/ψγ decay is measured to be Γ χ c 1 3872 → ψ 2 S γ Γ χ c 1 3872 → J / ψ γ = 1.67 ± 0.21 ± 0.12 ± 0.04 , where the first uncertainty is statistical, the second systematic and the third is due to the uncertainties on the branching fractions of the ψ(2S) and J/ψ mesons. The measured ratio makes the interpretation of the χc1(3872) state as a pure D0 D ¯ ∗ 0 + D ¯ 0 D*0 molecule questionable and strongly indicates a sizeable compact charmonium or tetraquark component within the χc1(3872) state.…”
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Search for dark QCD with emerging jets in proton-proton collisions at √𝑠 = 13 TeV by Hayrapetyan, A., Tumasyan, A., Adam, W., Andrejkovic, J. W., Bergauer, T., Chatterjee, S., Damanakis, K., Dragicevic, M., Hussain, P. S., Jeitler, M., Krammer, N., Li, A., Liko, D., Mikulec, I., Schieck, J., Schöfbeck, R.

“…As the dark sector quark showers and hadronizes, it produces long-lived dark mesons that subsequently decay into SM particles, resulting in a jet, known as an emerging jet, with multiple displaced vertices. …”
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